This video describes how the circulatory system works, how disease can affect blood vessels (atherosclerosis), and how doctors use angiography to test for coronary artery blockage.

Tiny electric currents flow through the heart muscle and cause them to contract, squeezing blood throughout the body. This animation shows the electrical system of the heart and how it is driven by a small patch of tissue called the cardiac pacemaker or sinoatrial node.

Provides an overview of the circulatory system including the blood vessels that supply the heart. When these coronary arteries become blocked, the vessels need to be bypassed with other blood vessels. The animation describes a coronary artery bypass graft surgery or CABG.

This narrated animation shows what happens in a myocardial infarction or heart attack. It shows how a blockage of a coronary artery causes a heart attack, leads to heart damage, and may lead to arrhythmias (abnormal electrical activity of the heart).